Install DataStax Enterprise 6.8 on Debian-based systems using APT

Use these instructions for installing DataStax Enterprise (DSE) 6.8 on Debian-based systems using APT.

Some things to know about installing DataStax Enterprise:

These instructions apply to all versions of DSE 6.8. For specific changes please see the DSE 6.8 release notes.
When installed from a package (Yum or APT), DSE runs as a service. The service initialization script is located in /etc/init.d/dse. Run levels are not set by the package.
This procedure installs DSE 6.8 and the DataStax Agent. It does not install OpsCenter, DataStax Studio, or DataStax Bulk Loader.
When connecting to DSE 6.8 from OpsCenter, use version OpsCenter 6.8; earlier versions are not supported. See DataStax OpsCenter compatibility with DSE.

When DSE is installed, it creates a cassandra user in the database. Do not use the cassandra user in production. Failing to do so is a security risk. See Adding a superuser login.

Prerequisites

Root or sudo access.
A supported platform.
Aptitude Package Management (APT) application.
Configure your operating system to use the latest version of Java 8:
- Recommended. The latest build of a TCK (Technology Compatibility Kit) Certified OpenJDK version 8. For example, OpenJDK 8 (1.8.0_242 minimum). DataStax’s recommendation changed due to the end of public updates for Oracle JRE/JDK 8. See Oracle Java SE Support Roadmap.
- Supported. Oracle Java SE 8 (JRE or JDK) (1.8.0_151 minimum)
Python 2.7.x or 3.6+. Both are supported for cqlsh. For older RHEL distributions, see Installing Python 2.7 on older RHEL-based package installations.

Hardware requirements

See Recommended production settings.

Procedure

End User License Agreement (EULA). By downloading this DataStax product, you agree to the terms of the EULA.

In a terminal window:

Verify that a required version of Java is installed:
```
java -version
```
DataStax recommends the latest build of a Technology Compatibility Kit (TCK) Certified OpenJDK version 8.

If OpenJDK, the results should look like:
```
openjdk version "1.8.0_242"
OpenJDK Runtime Environment (build 1.8.0_242-b09)
OpenJDK 64-Bit Server VM (build 25.242-b09, mixed mode)
```
If Oracle Java, the results should look like:
```
java version "1.8.0_241"
Java(TM) SE Runtime Environment (build 1.8.0_241-b13)
Java HotSpot(TM) 64-Bit Server VM (build 25.241-b13, mixed mode)
```
If not OpenJDK 8 or Oracle Java 8, see Installing the JDK.
Install the libaio package. For example:
```
sudo apt-get install libaio1
```

Add a DataStax repository file called /etc/apt/sources.list.d/datastax.sources.list:

echo "deb https://debian.datastax.com/enterprise/ stable main" | sudo tee -a /etc/apt/sources.list.d/datastax.sources.list

Add the DataStax repository key:

curl -L https://debian.datastax.com/debian/repo_key | sudo apt-key add -

Update the packages:
```
sudo apt-get update
```
Install the DSE packages:

Specify all packages; otherwise, the installation fails.
- Install the latest version (6.8.x):
```
sudo apt-get install dse-full
```
- Install an earlier 6.8.x version:
To view the available 6.8.x versions, see the Release notes.
```
sudo apt-get install dse=version_number-1 \
    dse-full=version_number-1 \
    dse-libcassandra=version_number-1 \
    dse-libgraph=version_number-1 \
    dse-libhadoop2-client-native=version_number-1 \
    dse-libhadoop2-client=version_number-1 \
    dse-liblog4j=version_number-1 \
    dse-libsolr=version_number-1 \
    dse-libspark=version_number-1 \
    dse-libtomcat=version_number-1
```
For example:

Specify all packages; otherwise, the installation fails.
```
sudo apt-get install dse=6.8.0-1 \
    dse-full=6.8.0-1 \
    dse-libcassandra=6.8.0-1 \
    dse-libgraph=6.8.0-1 \
    dse-libhadoop2-client-native=6.8.0-1 \
    dse-libhadoop2-client=6.8.0-1 \
    dse-liblog4j=6.8.0-1 \
    dse-libsolr=6.8.0-1 \
    dse-libspark=6.8.0-1 \
    dse-libtomcat=6.8.0-1
```
- Optional: Install the demos:
Installing the DSE demos is not recommended for production. Only install the demos in development environments to run tutorials.
```
sudo apt-get install dse-demos=version_number-1
```
Result

DSE is ready for additional configuration:
- For production, be sure to change the cassandra user. Failing to do so is a security risk. See Adding a superuser login.
- DSE provides several types of workloads (default is transactional). See startup options for service or stand-alone installations.
- Next Steps below provides links to related tasks and information.

Single-node cluster installations only:

Start DSE:
```
sudo service dse start
```

Verify that DSE is running by entering the nodetool status command:

nodetool status

Review the output to verify that DSE is running:

Datacenter: Cassandra
=====================
Status=Up/Down
|/ State=Normal/Leaving/Joining/Moving
--  Address    Load       Tokens  Owns    Host ID                               Rack
UN  127.0.0.1  82.43 KB   128     ?       40725dc8-7843-43ae-9c98-7c532b1f517e  rack1

Next Steps

You must change or delete the cassandra user created on installation. See Adding a superuser login.
Configure startup options: service or stand-alone.
If performing an upgrade, go to the next step in the Upgrade Guide.
Configuring DataStax Enterprise (DSE) - Settings for DSE Advanced Security, DSE In-Memory, DSE Advanced Replication, DSE Multi-Instance, DSE Tiered Storage, and more.
Default file locations for package installations
Default file locations for tarball installations
Changing logging locations after installation.
Starting and stopping DataStax Enterprise (DSE).
Preparing DataStax Enterprise (DSE) for production.
Recommended production settings.
Planning and testing DataStax Enterprise (DSE) cluster deployments.
Configuring the heap dump directory to avoid server crashes.
DataStax Studio documentation.
Installing DSE-compatible drivers.